Thanks to desalination plants, Israel is no longer worried about its water supply. So why aren't there more desalination plants in the United States?

California, I hear, has a big water problem,” Israeli Prime Minister Benjamin Netanyahu recently said on Bloomberg Television. “How come we don’t have a water problem? Because we use technology to solve it.”

The technology is Israeli’s four seawater desalination plants. The Middle Eastern nation, which sits on the eastern edge of the Mediterranean Sea, is 60 percent desert and has been struggling with drought for most of its existence. But with a fifth desalination plant set to open this year, Israel doesn’t have a water problem anymore. That’s because once the new plant comes online, more than 80 percent of Israel’s water will come from desalination.

Indeed, the largest users of desalinated water are in the Middle East, which uses about 70 percent of worldwide capacity, according to the U.S. Geological Survey. The desalination process essentially makes seawater drinkable by forcing it through reverse osmosis membranes that filter out salt and other impurities. There are about 300 desalination plants in the U.S. Most of them, however, are used for industrial purposes. Only about 13 percent of America’s domestic water supply -- that is, water for drinking, cooking and bathing -- comes from desalination. So why aren’t there more desalination plants in the U.S.?

That’s essentially what Netanyahu was wondering during his visit to drought-stricken California in March. Currently, the state has 17 proposals for plants but only half a dozen small ones currently operating along the 840-mile coastline. A desalination plant is being built in Carlsbad, Calif., that will wring 50 million gallons of freshwater a day from the sea and serve about 3.1 million people. The $1 billion project is set to open in 2016.

Part of the reason seawater desalination plants are rare in the U.S. is that the process is energy intensive and, as a result, expensive. Desalinated water can cost two times as much as water currently imported from other sources. The process is more common where energy is cheap, such as the oil-rich Middle East.

But perhaps a bigger reason there aren’t many seawater desalination plants in the U.S. is that there “is a risk in building facilities before we need them,” says Heather Cooley, water program director for the nonprofit Pacific Institute. She points to the Charles Meyer Desalination Facility in Santa Barbara as a cautionary tale. During the 1987-1992 drought, the coastal Southern California city built a plant as a hedge against an ongoing drought. But as soon as it was completed, the drought ended. Since there were cheaper options available, the city shut the facility down and it remains closed to this day.

Australia had a similar experience. During its Millennium Drought, which lasted more than 10 years starting in 1995, the country built six major seawater desalination plants. Today two of them are still in operation and four of them have been put in standby mode. “This is because, again, there are cheaper options available,” says Cooley. “Yes, we can build them from a technological standpoint, but they are energy intensive and expensive. We need to look at what all of the options are.”

Long before Israel built its first desalination plant, it was already a world leader in water conservation. In addition to desalination, Israel reuses treated sewage water for agriculture, runs a public education campaign to conserve water, monitors for leaks in its infrastructure using advanced software and runs computerized deep drip irrigation systems. These areas, Cooley says, are ones that California and the U.S. need to work on.

“Water conservation and efficiency is typically the cheapest, fastest way to reduce demand and essentially develop a new supply,” she says. “We’ve made significant improvements in California, but we still have a long way to go.”